The present invention is directed to a device for permitting the escape of persons from elevated locations. More particularly, the present invention is directed to a device for permitting the escape of persons from the upper stories of buildings, from bridges, from ski lifts, from amusement park rides, from work towers or from platforms.
Escape devices, such as fire escape devices for buildings, are well known in the art. Conventionally, such devices consist of a length of rope or cable wound on a spool mounted within a frame that includes speed limiting means such as brakes, clutches or speed governors. A person to be rescued attaches himself, or is attached, to a harness at the end of the cable or on the frame and jumps or falls from the building or other structure at a controlled speed due to the speed limiting means. However, conventional devices suffer from at least two types of shortcomings. First, they are either usable only once, or the cable must be rewound after each use, which is time consuming. Second, no rational means have been devised for arranging the escape device and the user so that the user can avoid bumping or crashing into the building while exiting or during descent.
For example, U.S. Pat. No. 4,457,400 to Donaldson et al discloses an emergency descent device which uses a planetary gear linkage and a centrifugal brake to control the descent speed. The device is attached directly to a harness and has a cable having an anchor at one end for securement to a building. Donaldson et al illustrates attachment to a projecting balcony in order to permit the user to drop from the building at a distance from the wall of the building.
However, if no such balcony happens to be available, difficulties arise during exit and descent from the building. For example, if it is necessary to break a window to gain access to the outside, the person attempting to escape (escaper) must crawl over the jagged glass of the broken window, without any buffer, while making an escape. Once the escaper has reached the exterior of the building, if he simply drops downward from the edge of the window the cable will extend downward along the surface of the building and the user will fall while bumping into any projections that may exist on the side surface of the building. Conversely, if the escaper leaps from the window with an outward velocity component, upon the tensioning of the cable 13, the reaction force of the cable will include a component which will cause the user to swing in an arc and forcefully crash against the side of the building. Neither result is desirable.
Donaldson et al proposes that each person in the building have his own fire escape device since the devices are not reusable.
U.S. Pat. No. 4,448,284 to Ciabo discloses another rescue device using friction braking and which is not reusable. Ciabo illustrates the rescue device as being attached to a large hook extending from the window. However, there is no reason to suppose that such a hook will be available, and if attached directly to the building, Ciabo will suffer from the same shortcomings as Donaldson et al with respect to the user contacting the building during descent.
An older design illustrated in U.S. Pat. No. 831,462 to Noyer discloses a fire escape device having several loops or belts attached to a single cable, as well as a crank handle by which the rope can be rewound for reuse. However, the logistical problems in trying to simultaneously secure several people to belts attached to a single rope, as well as the problem of the time necessary for rewinding the rope, make this design impractical.